The term 'theory' is nowadays most commonly defined in relation to the concept of 'scientific knowledge'. Yet, the etymological background of the term ('to observe') reminds us that theory is, in fact, a way of viewing objects and of relating them to one another within a particular kind of discourse. The word 'discourse' implies that we are dealing with linguistic structures and that, in the realm of cultural and social sciences, theory can therefore only be understood as a linguistic construct. In What is Theory?, Peter V. Zima argues that this concept of theory has never been adequately analysed. He asserts that social scientists have been dealing with concepts such as 'culture', 'ideology', 'language' and 'discourse' without ever attempting to define the concept of theory itself. This new study re-examines the most important theoretical debates of the twentieth-century and, in engaging with the critical work of Adorno, Horkheimer and Bakhtin, offers an alternative concept of theory, one that is dialectical and dialogical, relating theoretical positions to one another in order to test them in systematic confrontation. In a critical development of Popper's idea of refutability and testability, Zima's theory opens up new perspectives and reveals pitfalls and problems which the traditional approach often obscures. In this engaging and highly original study, Zima offers a new definition of theory from a cultural and sociological perspective, arguing that the encounter of heterogeneous points of view in critical dialogue can improve interaction and increase coherence in the humanities.